Screen-saver programs were designed to help avoid these effects by automatically changing the images on the screen during periods of user inactivity.įor CRTs used in public, such as ATMs and railway ticketing machines, the risk of burn-in is especially high because a stand-by display is shown whenever the machine is not in use. Cathode ray televisions, oscilloscopes and other devices that use CRTs are all susceptible to phosphor burn-in, as are plasma displays to some extent. When the same image is displayed on a CRT screen for long periods, the properties of the exposed areas of phosphor coating on the inside of the screen gradually and permanently change, eventually leading to a darkened shadow or 'ghost' image on the screen, called a screen burn-in. Purpose Screen protection īefore the advent of LCD screens, most computer screens were based on cathode ray tubes (CRTs).
